Ruonan Xu

Interleukin-17–producing CD4+ T cells increase with severity of liver damage in patients with chronic hepatitis B†

Interleukin‐17 (IL‐17)‐producing CD4+ T cells (Th17)‐mediated immune response has been demonstrated to play a critical role in inflammation‐associated disease; however, its role in chronic hepatitis B virus (HBV) infection remains unknown. Here we characterized peripheral and intrahepatic Th17 cells and analyzed their association with liver injury in a cohort of HBV‐infected patients including 66 with chronic hepatitis B (CHB), 23 with HBV‐associated acute‐on‐chronic liver failure (ACLF), and 30 healthy subjects as controls. The frequency of circulating Th17 cells increased with disease progression from CHB (mean, 4.34%) to ACLF (mean, 5.62%) patients versus healthy controls (mean, 2.42%). Th17 cells were also found to be largely accumulated in the livers of CHB patients. The increases in circulating and intrahepatic Th17 cells positively correlated with plasma viral load, serum alanine aminotransferase levels, and histological activity index. In vitro, IL‐17 can promote the activation of myeloid dendritic cells and monocytes and enhance the capacity to produce proinflammatory cytokines IL‐1β, IL‐6, tumor necrosis factor (TNF)‐α, and IL‐23 in both CHB patients and healthy subjects. In addition, the concentration of serum Th17‐associated cytokines was also increased in CHB and ACLF patients. Conclusion: Th17 cells are highly enriched in both peripheral blood and liver of CHB patients, and exhibit a potential to exacerbate liver damage during chronic HBV infection. (HEPATOLOGY 2009.)

Human umbilical cord mesenchymal stem cells improve liver function and ascites in decompensated liver cirrhosis patients.

Decompensated liver cirrhosis (LC), a life‐threatening complication of chronic liver disease, is one of the major indications for liver transplantation. Recently, mesenchymal stem cell (MSC) transfusion has been shown to lead to the regression of liver fibrosis in mice and humans. This study examined the safety and efficacy of umbilical cord‐derived MSC (UC‐MSC) in patients with decompensated LC. A total of 45 chronic hepatitis B patients with decompensated LC, including 30 patients receiving UC‐MSC transfusion, and 15 patients receiving saline as the control, were recruited; clinical parameters were detected during a 1‐year follow‐up period. No significant side‐effects and complications were observed in either group. There was a significant reduction in the volume of ascites in patients treated with UC‐MSC transfusion compared with controls (P < 0.05). UC‐MSC therapy also significantly improved liver function, as indicated by the increase of serum albumin levels, decrease in total serum bilirubin levels, and decrease in the sodium model for end‐stage liver disease scores. UC‐MSC transfusion is clinically safe and could improve liver function and reduce ascites in patients with decompensated LC. UC‐MSC transfusion, therefore, might present a novel therapeutic approach for patients with decompensated LC.

Human Mesenchymal Stem Cell Transfusion Is Safe and Improves Liver Function in Acute-on-Chronic Liver Failure Patients

Acute‐on‐chronic liver failure (ACLF) is a severe, life‐threatening complication, and new and efficient therapeutic strategies for liver failure are urgently needed. Mesenchymal stem cell (MSC) transfusions have been shown to reverse fulminant hepatic failure in mice and to improve liver function in patients with end‐stage liver diseases. We assessed the safety and initial efficacy of umbilical cord‐derived MSC (UC‐MSC) transfusions for ACLF patients associated with hepatitis B virus (HBV) infection. A total of 43 ACLF patients were enrolled for this open‐labeled and controlled study; 24 patients were treated with UC‐MSCs, and 19 patients were treated with saline as controls. UC‐MSC therapy was given three times at 4‐week intervals. The liver function, adverse events, and survival rates were evaluated during the 48‐week or 72‐week follow‐up period. No significant side effects were observed during the trial. The UC‐MSC transfusions significantly increased the survival rates in ACLF patients; reduced the model for end‐stage liver disease scores; increased serum albumin, cholinesterase, and prothrombin activity; and increased platelet counts. Serum total bilirubin and alanine aminotransferase levels were significantly decreased after the UC‐MSC transfusions. UC‐MSC transfusions are safe in the clinic and may serve as a novel therapeutic approach for HBV‐associated ACLF patients.

A pilot study of umbilical cord‐derived mesenchymal stem cell transfusion in patients with primary biliary cirrhosis

BACKGROUND AND AIM Ursodeoxycholic acid (UDCA) treatment is an effective medical therapy for patients with primary biliary cirrhosis (PBC); however, 40% of PBC patients show an incomplete response to the UDCA therapy. This study aimed to investigate the safety and efficacy of umbilical cord-derived mesenchymal stem cell (UC-MSC) transfusion in PBC patients with an incomplete response to UDCA. METHODS We conducted a single-arm trial that included seven PBC patients with a suboptimal response to UDCA treatment. UC-MSCs were first cultured, and then 0.5 × 10(6) cells/kg body weights were infused through a peripheral vein. UC-MSCs were given three times at 4-week intervals, and patients were followed up for 48 weeks. Primary outcomes were to evaluate the safety and feasibility of UC-MSC treatment, and secondary outcomes were to evaluate liver functions and patients quality of life. RESULTS No obvious side-effects were found in the patients treated with UC-MSCs. Symptoms such as fatigue and pruritus were obviously alleviated in most patients after UC-MSC treatment. There was a significant decrease in serum alkaline phosphatase and γ-glutamyltransferase levels at the end of the follow-up period as compared with baseline. No significant changes were observed in serum alanine aminotransferase, aspartate aminotransferase, total bilirubin, albumin, prothrombin time activity, international normalized ratio, or immunoglobulin M levels. The Mayo risk score, a prognostic index, was also stable during the treatment and follow-up period. CONCLUSIONS UC-MSC transfusion is feasible and well tolerated in patients with PBC who respond only partially to UDCA treatment, thus representing a novel therapeutic approach for patients in this subgroup. A larger, randomized controlled cohort study is warranted to confirm the clinical efficacy of UC-MSC transfusion.

The role of neutrophils in the development of liver diseases

Liver disease encompasses a wide variety of liver conditions, including liver failure, liver cirrhosis and a spectrum of acute and chronic hepatitis, such as alcoholic, fatty, drug, viral and chronic hepatitis. Liver injury is a primary causative factor in liver disease; generally, these factors include direct liver damage and immune-mediated liver injury. Neutrophils (also known as neutrophilic granulocytes or polymorphonuclear leukocytes (PMNs)) are the most abundant circulating white blood cell type in humans, and PMNs are a major innate immune cell subset. Inappropriate activation and homing of neutrophils to the microvasculature contributes to the pathological manifestations of many types of liver disease. This review summarizes novel concepts of neutrophil-mediated liver injury that are based on current clinical and animal model studies.

Liver fibrosis: mechanisms of immune-mediated liver injury.

Liver fibrosis and its end-stage consequence, cirrhosis, represent the final common pathway of virtually all chronic liver diseases. Research into hepatic stellate cell activation, imbalance of the extracellular matrix synthesis and degradation and the contribution of cytokines and chemokines has further elucidated the mechanisms underlying fibrosis. Furthermore, clarification of changes in host adaptive and innate immune systems has accelerated our understanding of the association between liver inflammation and fibrosis. Continued elucidation of the mechanisms of hepatic fibrosis has provided a comprehensive model of fibrosis progression and regression. This review summarizes the current concepts of improvements that have been made in the field of fibrosis.

Implications of the immunoregulatory functions of mesenchymal stem cells in the treatment of human liver diseases.

Transplantation of mesenchymal stem cells (MSCs) has been recently studied in animal models, and in clinical trials of patients with fulminant hepatic failure, end-stage liver diseases and inherited metabolic disorders. Modulatory cytokines produced by MSCs can inhibit immunocyte proliferation and migration to the liver, thereby attenuating inflammatory injury and reducing hepatocyte apoptosis. In addition, MSCs play an important role in regressing liver fibrosis and in supporting the function, proliferation and differentiation of endogenous hepatocytes under appropriate conditions. Although remarkable progress has been achieved in basic and clinical MSC studies, optimal therapeutic regimens for the clinical application of MSCs, such as optimal doses, transplantation routine and interval period for transplantation, need to be elucidated in detail. Furthermore, the long-term safety and therapeutic efficacy of MSC transplantation should be evaluated in future clinical trials. This review summarizes our current understanding of the immunomodulatory effects of MSC therapies on human liver diseases.

Reversal of B-cell hyperactivation and functional impairment is associated with HBsAg seroconversion in chronic hepatitis B patients

B cells play an important role in the clearance of hepatitis B virus (HBV) and protection against reinfection. However, the functional characteristics of these cells that are associated with the outcome of chronic HBV infection remain unknown. We comprehensively investigated the frequency, phenotype, and function of peripheral B-cell subsets from CHB patients in different phases: immune tolerance (IT), immune activation (IA), immune clearance (IC), responders with HBsAg seroconversion (resolved patients, RP), and healthy controls (HC). IA patients displayed lower percentages of peripheral blood memory B cells compared with the other groups. Overall polyclonal activation of B cells, indicated by higher levels of activation markers and secretion of IgG and IgM, was observed in IA patients. This B-cell hyperactivation could be induced by increased IFN-α and soluble CD40 ligands in IA patients. Notably, the expression of the co-stimulator molecule CD80 and serum HBsAb and the frequency of HBsAg-specific B cells were significantly decreased in IT, IA, and IC patients compared with HC subjects. More importantly, the B-cell hyperactivation, co-stimulatory molecule downregulation and HBsAg-specific B-cell impairment were reversed in RP patients. The reversal of B-cell hyperactivation and functional impairment is associated with HBsAg seroconversion in chronic hepatitis B patients.Cellular & Molecular Immunology advance online publication, 6 April 2015; doi:10.1038/cmi.2015.25

Safety and immunological responses to human mesenchymal stem cell therapy in difficult-to-treat HIV-1-infected patients

Objective:HAART largely decreases morbidity and mortality in chronic HIV-1-infected patients, but immune nonresponders (INRs) with full viral suppression still fail to reverse the immune deficiency. This study evaluated the safety and immunological responses of human umbilical cord mesenchymal stem cell (MSC) therapy in HIV-1-infected INRs. Design and Methods:A total of 13 HIV-1-infected INRs were enrolled in this pilot prospectively open-labeled controlled clinical trial. Seven patients were administered three umbilical cord-MSC transfusions at 1-month interval during 12-months of follow-up, whereas six control patients were treated with saline in parallel. Immunological parameters were monitored in these patients throughout the trial. Results:All patients tolerated the umbilical cord-MSC transfusions well throughout the trial. The umbilical cord-MSC transfusions preferentially increased circulating naive and central memory CD4 T-cell counts and restored HIV-1-specific IFN-&ggr; and IL-2 production in the INRs. These enhancements in immune reconstitution were also associated with the reduction of systemic immune activation and inflammation in vivo. Conclusions:umbilical cord-MSC transfusions are well tolerated and can efficiently improve host immune reconstitution in INRs, suggesting that such treatments may be used as a novel immunotherapeutic approach to reversing immune deficiency in HIV-1-infected INRs (ClinicalTrials.gov identifier: NCT01213186).

Complement 5a stimulates hepatic stellate cells in vitro, and is increased in the plasma of patients with chronic hepatitis B

Complement 5a (C5a) is a critical modulator of liver immunity. In this study, we investigated the role of C5a and its receptor in liver fibrosis in patients with hepatitis B virus infection. We found that plasma C5a concentration was significantly increased in patients with chronic hepatitis B, particularly in those patients with higher grade and stage scores. Further analysis indicated that the increased C5a concentration was positively correlated with clinical parameters reflecting liver fibrosis severity, including type IV collagen and procollagen type III N‐terminal peptide. Our in vitro data indicated that the C5a receptor is highly expressed in hepatic stellate cells (HSCs). Addition of C5a significantly activated HSCs and up‐regulated α‐smooth muscle actin, hyaluronic acid and type IV collagen expression. Also, addition of C5a could inhibit the spontaneous and soluble tumour necrosis factor‐related apoptosis‐inducing ligand‐induced apoptosis of HSCs. These findings highlight the potential role of C5a in the regulation of liver fibrosis.